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From:   Ard Biesheuvel <ardb@kernel.org>
To:     linux-efi@vger.kernel.org
Cc:     keescook@chromium.org, Ard Biesheuvel <ardb@kernel.org>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Arend van Spriel <aspriel@gmail.com>,
        Franky Lin <franky.lin@broadcom.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        Kalle Valo <kvalo@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Gregory Greenman <gregory.greenman@intel.com>,
        linux-input@vger.kernel.org, linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com
Subject: [PATCH 2/4] Input: applespi - avoid efivars API and invoke EFI services directly
Date:   Fri, 17 Jun 2022 19:48:49 +0200
Message-Id: <20220617174851.1286026-3-ardb@kernel.org>
In-Reply-To: <20220617174851.1286026-1-ardb@kernel.org>
References: <20220617174851.1286026-1-ardb@kernel.org>
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This driver abuses the efivar API, by using a few of its helpers on
entries that were not instantiated by the API itself. This is a problem
as future cleanup work on efivars is complicated by this.

So let's just switch to the get/set variable runtime wrappers directly.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/input/keyboard/applespi.c | 42 +++++++-------------
 1 file changed, 14 insertions(+), 28 deletions(-)

diff --git a/drivers/input/keyboard/applespi.c b/drivers/input/keyboard/applespi.c
index d1f5354d5ea2..cbc6c0d4670a 100644
--- a/drivers/input/keyboard/applespi.c
+++ b/drivers/input/keyboard/applespi.c
@@ -1597,52 +1597,38 @@ static u32 applespi_notify(acpi_handle gpe_device, u32 gpe, void *context)
 
 static int applespi_get_saved_bl_level(struct applespi_data *applespi)
 {
-	struct efivar_entry *efivar_entry;
+	efi_status_t sts = EFI_NOT_FOUND;
 	u16 efi_data = 0;
-	unsigned long efi_data_len;
-	int sts;
-
-	efivar_entry = kmalloc(sizeof(*efivar_entry), GFP_KERNEL);
-	if (!efivar_entry)
-		return -ENOMEM;
-
-	memcpy(efivar_entry->var.VariableName, EFI_BL_LEVEL_NAME,
-	       sizeof(EFI_BL_LEVEL_NAME));
-	efivar_entry->var.VendorGuid = EFI_BL_LEVEL_GUID;
-	efi_data_len = sizeof(efi_data);
+	unsigned long efi_data_len = sizeof(efi_data);
 
-	sts = efivar_entry_get(efivar_entry, NULL, &efi_data_len, &efi_data);
-	if (sts && sts != -ENOENT)
+	if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE))
+		sts = efi.get_variable(EFI_BL_LEVEL_NAME, &EFI_BL_LEVEL_GUID,
+				       NULL, &efi_data_len, &efi_data);
+	if (sts != EFI_SUCCESS && sts != EFI_NOT_FOUND)
 		dev_warn(&applespi->spi->dev,
-			 "Error getting backlight level from EFI vars: %d\n",
+			 "Error getting backlight level from EFI vars: 0x%lx\n",
 			 sts);
 
-	kfree(efivar_entry);
-
-	return sts ? sts : efi_data;
+	return sts != EFI_SUCCESS ? -ENODEV : efi_data;
 }
 
 static void applespi_save_bl_level(struct applespi_data *applespi,
 				   unsigned int level)
 {
-	efi_guid_t efi_guid;
+	efi_status_t sts = EFI_UNSUPPORTED;
 	u32 efi_attr;
-	unsigned long efi_data_len;
 	u16 efi_data;
-	int sts;
 
-	/* Save keyboard backlight level */
-	efi_guid = EFI_BL_LEVEL_GUID;
 	efi_data = (u16)level;
-	efi_data_len = sizeof(efi_data);
 	efi_attr = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS |
 		   EFI_VARIABLE_RUNTIME_ACCESS;
 
-	sts = efivar_entry_set_safe((efi_char16_t *)EFI_BL_LEVEL_NAME, efi_guid,
-				    efi_attr, true, efi_data_len, &efi_data);
-	if (sts)
+	if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE))
+		sts = efi.set_variable(EFI_BL_LEVEL_NAME, &EFI_BL_LEVEL_GUID,
+				       efi_attr, sizeof(efi_data), &efi_data);
+	if (sts != EFI_SUCCESS)
 		dev_warn(&applespi->spi->dev,
-			 "Error saving backlight level to EFI vars: %d\n", sts);
+			 "Error saving backlight level to EFI vars: 0x%lx\n", sts);
 }
 
 static int applespi_probe(struct spi_device *spi)
-- 
2.35.1